(a) Field of the Invention
The present invention relates to a plasma display device and a driving method thereof. More particularly, the present invention relates to a method for allocating a sustain pulse to a plurality of subfields that form one frame.
(b) Description of the Related Art
A plasma display device is a flat panel display device that uses plasma generated by a gas discharge process to display characters or images. In general, one frame of the plasma display device is divided into a plurality of subfields, each having a corresponding brightness weight, to drive the plasma display device. Turn-on/turn-off cells (i.e., cells to be turned on or off) are selected during an address period of each subfield, and a sustain discharge operation is performed on the turn-on cells to display an image during a sustain period. Grayscales are expressed by a combination of weights of the subfields that are used to perform a display operation.
In a display panel of the plasma display device, a plurality of row electrodes and a plurality of column electrodes are formed, and discharge cells are formed where the row electrodes cross the column electrodes. Accordingly, currents flowing to the row electrodes vary according to the number of the turn-on cells along the row electrode, and a voltage drop occurs according to the currents. The voltage drop is reduced as the number of turn-on cells of the row electrode is reduced and luminance in one discharge cell is increased when the voltage drop is reduced. That is, since the luminance expressed by one subfield varies according to the number of turn-on cells of the row electrodes, a luminance deviation at the row electrode may occur for the same gray scale.